In Amsterdam; from Charles Burney's Present State of Music in Germany, the Netherlands, and United Provinces: Or, the Journal of a Tour Through Those Countries, Undertaken to Collect Materials for a General History of Music.
Although Burney can't bring himself to fully commit to his goal of neutral observation, the attitude that he thinks he has taken, namely to describe and not judge, is actually quite modern.
This book preceded his real masterwork, a four volume history of music. Here is his transcription of Jewish singing in the synagogue (at the end of the section on Hebrew music, vol. I; read the notes from right to left):
This transcription is preceded by a short discussion on modern Jewish music, with an interesting anecdote.